Support for vertically adjustable seats



y 1949- c. E. E. LUNDQUIST 2,476,258 SUPPORT FOR VERTICALLY ADJUSTABLE SEATS 7 Filed. April 29, 1944 '2 Sheets-Sheet 1 NVEN R.

ATTORNEEY July 12, 1949.

Filed- April 29, 1944 C. E. E. LUNDQUIST SUPPORT FOR VERTICALLY ADJUSTABLE SEATS w 'w w 2 Sheets-Sheet 2 haw, y/A

. CM A TTORNEY Patented July 12, 1949 Q I My invention relates to "chairs, 'iriore "particularly'for ofiiceu'se. Still niorepart'icularly my invention relates to chairs having a frame to support a rotatable seat adapted 'to be raised and lowered, said frair-ie b'eiri'g 1 provided with a tubular hub portion for a spindle having the seait connected; thereto. One obj ect of the invention is to provide a chair of said typawhich is cheap and permits of being manufactured with ash-iall consumption of material only," and which-at the sametirrie p'ossessesgreatstrength and "st; ability.

Further objects --a-ndadvantages; of the -invention will be apparent frorrrt lowing'description considered incon-nectidn with the accmpanying drawings,- which form apart of 'this specification, and ofwhich:

Figs. 1 andla-are-perspctive viewsof office chairs constructed in accordance with the invention; I I 7 Figs. 2 and 5 are sectional views-9n anf' enlarged scale ontl'ie lines-IIII--and'-V=V, respectively, 6f -1 Figs; 3 -arid- -4- aresectional views on 'tlie lines III-411 and IV-IV of Figs. 1 and 1a respectively.

Corresponding parts are designated throughout by the same reference numerals in the various drawings.

In the embodiments illustrated, the chair is provided with two frames l0, l2 constructed in accordance with the invention. The lower frame is composed of a tubular piece 14 and a number, in the present case four, of upper and lower strap braces I8, 20, which are of a curved cross section (Fig. 3).

While these strap braces are in Fig. 1a constituted by the slotted end portions of the tubular piece [4, the upper and lower strap braces of Fig. 1 are connected in pairs with a central portion [6, which is rigidly connected to the tubular piece l4 in any suitable manner, for instance by welding. The central portions [6 extend along generatrixes of the tube l4 and follow with their curved profile over the outer surface thereof, as will appear from Fig. 2. The central portions l6 of the strap braces need not bear on each other, but may be arranged in a spaced relationship.

The strap braces are bent outwardly at both e ds of the tubula piece 1 the upper part It beingldngerfa'd'ffd' F ferangm'jivith the axisofth'e' tube M aramdbestuemwerpcrtion 20.

one another in here "they "are rthe rniofre, they a'e'r fm or w en a'h's of bolts 22.

, n ternalith'readsferi ga'getl I vertical" minare -331:; aiid finayfsfipppit the frame 12 at theul p of the. tube. The-fragment is csnstructe trail rfrn'arlhefiasithe fraiffie m, and consenuennycbzis-ists- "f a tubuiar'pi atable "on the cordingtofi ig. "1* tbn tions 1; thetubufar pl nec'ted*'ih"pair's to a is rigidly connected 1: t efor instance by welding. The central portions 34 extend in parallel to generatrixes of the tube. The lower brace portions 38 are then bent outwardly at acute angles, while the upper brace portions 36 may extend in a horizontal or approximately horizontal direction. The free ends of the individual braces are connected with each other and with a chair seat 40, for instance by means of rivets 42.

The upper frame I2 is held in an axial direction between a nut 46 screwed on spindle 30 and a ring 44, which is secured on the spindle 30, for instance by welding. A ring 48 may be interposed between the ring 44 and the frame I2, said ring 48 being preferably fixed to the frame, as for example by welding, so as to turn with the frame. The bearing surfaces 54 (Fig. 5) between the rings 44 and 48 extend conically. By the fact that they are also situated at a greater radial distance from the axis of the spindle 30 than are the contact surfaces between the threads of the spindle and the lower frame H], the friction between the surfaces 50,-wil1 be greater than in said threads.

In the embodiments illustrated, a sleeve 5ft movable in the axial direction over the spindle threads 28 above the irame ID. This sleeve may be provided with a shoulder 56 (Fig. 4) on the inside thereof, said shoulder running in a guide slot 58 in the spindle threads 28. A stud 50 extends downwardly from the sleeve 54. In the position shown in Figs. 1 and 1a, such stud is located between two strap braces of the frame l0. By this means positive locking will be obtained between the spindle 30 and the frame so that when the chair seat 40 is rotated, the upper frame I2 will turn relative to the upper portion of the spindle 30, which has no threads. When the sleeve 54 is moved upwardly so that the stud 60 is relieved of the frame I 0, said stud being, if desired, held in place in the slot 58 by means of an arresting spring 62, the spindle may turn relative to thelower frame ID, for the purpose of adjusting the height of the chair seat 40. By the friction surfaces 58 the turning movement now takes place between the frame I0 and the spindle, although the upper frame I2 is running freely thereon. After the sleeve has been returned to the position shown in Figs. 1 and 1a, the spindle 30 is again locked relative to the frame It).

Extending through a slot in one of the lower strap brace portions 38 of the frame I 2 is an arm 64, which is preferably rigidly connected with the central portion 34 of the same strap brace, for instance by welding.

In the embodiments illustrated, a novel form of joint is shown between the back supporting arms 64 and 18. This joint forms the claimed subject matter of my copending divisional application, Serial No. 2512, filed January 15, 1948.

While more or less specific embodiments of the invention have been shown, it is to be understood that the same are for purpose of illustration only, and that the invention is not to be limited thereby, but its scope is to be determined by the scope of the appended claims.

What I claim is:

1. In an adjustable chair, a tubular member for engaging a rotatable spindle, a plurality of arms having their central portions integral with said member, the end portions of each arm extending in a radial plane from the upper and lower ends, respectively, of said member, and means for joining the free ends of the end portions of each arm together.

2. In an adjustable chair, a tubular member for engaging a rotatable spindle, said tubular member being split longitudinally at its end portions to form a plurality of arms integral therewith and extending in radial planes from the upper and lower ends, respectively, of said member, and means for joining together the free ends of the arms in the same radial plane.

3. In an adjustable chair, a tubular member for engaging a rotatable spindle, a plurality of arms having their central portions integral with said member, the end portions of each arm extending in a radial plane from the upper and lower ends, respectively, of said member, a seat member, and means for joining the free ends of the end portions of each arm together and to said seat member.

4. In an adjustable chair, a tubular member having a central portion for encircling a rotatable spindle and end portions longitudinally slit to provide a plurality of pairs of arms bent radially outwardly from said central portion at each end thereof, said pairs of arms being arranged in a plurality of radial planes respectively, and

means for joining the free end portions of the arms of each of the pairs together.

CARL ERNST EDVARD LUNDQUIST.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 46,121 Ludke Jan. 31, 1865 153,014 Ramseyer July 14, 1874 401,379 Sammons Apr. 16, 1889 535,348 Bolens et al Mar. 12, 1895 535,455 Meyer Mar. 12, 1895 552,502 Andrews Jan. 7, 1896 714,764 Watkins Dec. 2, 1902 847,529 Trumbull Mar. 19, 1907 892,054 Holtzman June 30, 1908 1,072,693 Brackley Sept. 9, 1913 1,101,402 Carroll June 23, 1914 1,453,650 Wilson May 1, 1923 1,864,814 Gallagher et al June 28, 1932 2,305,152 Forsyth Dec. 15, 1942 Certificate of Correction Patent No. 2,476,258 July 12, 1949 CARL ERNST EDVARD LUNDQUIST Itis hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows:

. Column 4, line 45, list of references cited, after 1,101,402 Carroll 2 June 23, 1914" insert 1,110,142 Piner Sept. 8, 1914; after line i8 i 1is ert 2,342,921 Oramer et al. Feb. 29, 1.944;

and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 14th day of February, A. D. 1950.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

